“Let ’em have it!” called Tom in a low voice, and the electric rifles sent out their stunning charges.  Several natives in the front rank dropped, and there was a cry of fear and wonder from the others.  Then, after a moment’s hesitation they pressed on again.

“Once more!” cried Tom.

Again the electric rifles spoke, and half a score went down unconscious, but not seriously hurt.  In a few hours they would be as well as ever, such was the merciful charge that Tom Swift and the others used in the rifles.

The third time they fired, and this was too much for the natives.  They could not battle against an unseen and silent enemy who mowed them down like a field of grain.  With wild yells they fled back along the trail they had come.

“I guess that does it!” cried Tom.  “We’d better join the others now.”

Mounting their mules, they galloped back to where San Pedro and his natives were pressing forward.

“Did you have the honor of defeating them,” the head mule driver asked.

“I had the honor,” answered Tom, with a grim smile.

Then they pressed on, but there was no more danger.  That night they camped in a peaceful valley and were not disturbed, and the following day they put a good many miles behind them.  On the advice of San Pedro, they avoided the next two villages as they realized that they were in the war zone, and then they headed for a large town where Tom was sure he would hear some news of the giants.

They had to camp twice at night before reaching this town, and when they did get to it they were warmly welcomed, for white explorers had been there years before, and had treated the natives well.  Tom distributed many trinkets among the head men and won their good will so that the party was given comfortable huts in which to sleep, and a plentiful supply of provisions.

“Can you arrange for a talk with the chief?” asked Tom of San Pedro that night.  “I want to ask him about certain things.”

“About where you can find giant flowers?” asked the mule driver with a quick look.

“Yes—­er—­and other giant things,” replied Tom.  “I fix,” answered San Pedro shortly, but there was a queer look on his face.

A few hours later Tom was summoned to the hut of the chief of the town, and thither he went with Ned, Mr. Damon and San Pedro as interpreter, for the natives spoke a jargon of their own that Tom could not understand.

There were some simple ceremonies to observe, and then Tom found himself facing the chief, with San Pedro by his side.  After the greetings, and an exchange of presents, Tom giving him a cheap phonograph with which the chief was wildly delighted, there came the time to talk.

“Ask him where the giant men live?” our hero directed San Pedro, believing that the time had now come to disclose the object of his expedition.

“Giant men, Senor Swift?  I thought it was giant plants—­orchids—­you were after,” exclaimed San Pedro.